"""TDD — mpack.index job: object writes, object refs, idempotency.

The one principle: Content-addressing is a proof, not a label.
sha256(wire_bytes) == mpack_key already authenticated every byte in the
mpack — including every object's content and its declared ID.

Invariants:
  1. After job runs: musehub_objects has one row per object with mpack:// URI.
  2. After job runs: musehub_object_refs has rows for every (repo_id, object_id).
  3. No per-object sha256 re-verification — that is checking the work of the hash.
  4. Job is idempotent — running it twice produces identical DB state.
  5. Return dict includes mpack_index_written, elapsed_ms (and other counts).
"""
from __future__ import annotations

import datetime
import hashlib
import pathlib

import msgpack
import pytest
import pytest_asyncio

from httpx import AsyncClient, ASGITransport
from sqlalchemy import func, select
from sqlalchemy.ext.asyncio import AsyncSession

from musehub.auth.request_signing import MSignContext, require_signed_request, optional_signed_request
from musehub.db.musehub_repo_models import MusehubObject, MusehubObjectRef, MusehubRepo
from musehub.db.database import get_db
from musehub.main import app

from muse.core.object_store import write_object
from muse.core.mpack import build_mpack
from muse.core.paths import muse_dir
from muse.core.snapshot import compute_commit_id, compute_snapshot_id
from muse.core.commits import CommitRecord, write_commit
from muse.core.refs import write_branch_ref
from muse.core.snapshots import SnapshotRecord, write_snapshot
from muse.core.types import blob_id
from musehub.types.json_types import JSONObject


_AUTH_CTX = MSignContext(
    handle="gabriel",
    identity_id="sha256:" + "0" * 64,
    is_agent=False,
    is_admin=True,
)

# Small enough to be fast, large enough to exercise batching
_N_FILES       = 30
_N_COMMITS     = 15
_FILES_CHANGED = 3
_BLOB_SIZE     = 256


# ── fixtures ───────────────────────────────────────────────────────────────

@pytest_asyncio.fixture()
async def client(db_session: AsyncSession) -> None:
    async def _override_get_db() -> None:
        yield db_session

    app.dependency_overrides[get_db] = _override_get_db
    app.dependency_overrides[require_signed_request] = lambda: _AUTH_CTX
    app.dependency_overrides[optional_signed_request] = lambda: _AUTH_CTX

    async with AsyncClient(
        transport=ASGITransport(app=app),
        base_url="https://localhost:1337",
    ) as c:
        yield c

    app.dependency_overrides.clear()


@pytest_asyncio.fixture()
async def repo(client: AsyncClient) -> None:
    resp = await client.post(
        "/api/repos",
        json={"owner": "gabriel", "name": "mpack-index-test", "visibility": "public", "initialize": False},
    )
    assert resp.status_code in (200, 201), resp.text
    data = resp.json()
    yield data["slug"]
    await client.delete(f"/api/repos/{data['repoId']}")


def _make_repo(tmp: pathlib.Path) -> tuple[pathlib.Path, str, dict]:
    """Return (repo_path, head_commit_id, mpack_dict)."""
    tmp.mkdir(parents=True, exist_ok=True)
    dot = muse_dir(tmp)
    dot.mkdir()
    (dot / "repo.json").write_text('{"repo_id":"idx-test","owner":"gabriel"}')
    for d in ("commits", "snapshots", "objects"):
        (dot / d).mkdir()
    (dot / "refs" / "heads").mkdir(parents=True)
    (dot / "HEAD").write_text("ref: refs/heads/main\n")
    (dot / "config.toml").write_text("")

    blob_ids: list[str] = []
    for i in range(_N_FILES):
        data = f"base-{i:04d}".encode() + b"x" * _BLOB_SIZE
        oid = blob_id(data)
        write_object(tmp, oid, data)
        blob_ids.append(oid)

    base_manifest = {f"src/file_{i:04d}.py": blob_ids[i] for i in range(_N_FILES)}
    parent = None
    tip = ""
    ts = datetime.datetime(2026, 1, 1, tzinfo=datetime.timezone.utc)

    for i in range(_N_COMMITS):
        manifest = dict(base_manifest)
        for j in range(_FILES_CHANGED):
            idx = (i * _FILES_CHANGED + j) % _N_FILES
            raw = f"c{i:04d}-f{j}".encode() + b"y" * _BLOB_SIZE
            oid = blob_id(raw)
            write_object(tmp, oid, raw)
            manifest[f"src/file_{idx:04d}.py"] = oid

        sid = compute_snapshot_id(manifest)
        write_snapshot(tmp, SnapshotRecord(snapshot_id=sid, manifest=manifest))
        msg = f"commit-{i:05d}"
        cid = compute_commit_id(
            parent_ids=[parent] if parent else [],
            snapshot_id=sid,
            message=msg,
            committed_at_iso=ts.isoformat(),
            author="gabriel",
        )
        write_commit(tmp, CommitRecord(
            commit_id=cid, branch="main",
            snapshot_id=sid, message=msg, committed_at=ts,
            parent_commit_id=parent, parent2_commit_id=None,
            author="gabriel", metadata={}, structured_delta=None,
            sem_ver_bump="none", breaking_changes=[],
            agent_id="", model_id="", toolchain_id="",
            prompt_hash="", signature="", signer_key_id="",
        ))
        parent = cid
        tip = cid
        ts += datetime.timedelta(seconds=60)

    write_branch_ref(tmp, "main", tip)
    mpack = build_mpack(tmp, [tip], have=[])
    return tmp, tip, mpack


async def _push_mpack(
    repo_slug: str,
    mpack: JSONObject,
    head: str,
    db_session: AsyncSession,
) -> str:
    """Store mpack in MemoryBackend and create a mpack.index job row. Returns job_id.

    Does NOT call push/unpack-mpack (that route enqueues background jobs and is
    tested separately). Creates the job row directly so tests can call
    process_mpack_index_job in isolation.
    """
    import musehub.storage.backends as _backends_mod
    from datetime import datetime, timezone
    from musehub.core.genesis import compute_job_id as _compute_job_id
    from musehub.db.musehub_jobs_models import MusehubBackgroundJob

    repo_row = (await db_session.execute(
        select(MusehubRepo).where(MusehubRepo.slug == repo_slug)
    )).scalar_one()
    repo_id = repo_row.repo_id

    wire_bytes = msgpack.packb(mpack, use_bin_type=True)
    mpack_key = "sha256:" + hashlib.sha256(wire_bytes).hexdigest()
    n_objects = len(mpack.get("blobs") or [])

    # Store directly in the MemoryBackend patched by the conftest autouse fixture.
    backend = _backends_mod.get_backend()
    await backend.put_mpack(mpack_key, wire_bytes)

    now = datetime.now(tz=timezone.utc)
    job_id = _compute_job_id(repo_id, "mpack.index", now.isoformat())
    db_session.add(MusehubBackgroundJob(
        job_id=job_id,
        repo_id=repo_id,
        job_type="mpack.index",
        payload={
            "mpack_key": mpack_key,
            "pusher_id": "sha256:" + "0" * 64,
            "branch": "main",
            "head": head,
            "force": False,
            "declared_objects_count": n_objects,
        },
        status="pending",
        created_at=now,
        attempt=0,
    ))
    await db_session.flush()
    return job_id


# ── Phase 1 tests ──────────────────────────────────────────────────────────

@pytest.mark.asyncio
async def test_objects_written_to_minio_after_job(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """After mpack.index runs: every object blob is retrievable from MinIO by object_id.

    This is the load-bearing test. Fetch/clone/pull are all blocked until
    objects are at their sha256 addresses in storage.
    """
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job
    result = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    raw_objects = mpack.get("blobs") or []
    assert raw_objects, "mpack must contain objects"

    # Phase 2: objects are stored via mpack URI (no individual MinIO writes).
    # Verify musehub_objects rows exist and storage_uri points to the mpack.
    all_oids = [obj["object_id"] for obj in raw_objects]
    rows = (await db_session.execute(
        select(MusehubObject).where(MusehubObject.object_id.in_(all_oids))
    )).scalars().all()
    row_map = {r.object_id: r for r in rows}

    missing = [oid for oid in all_oids if oid not in row_map]
    assert not missing, (
        f"{len(missing)}/{len(raw_objects)} objects have no musehub_objects row after job: "
        f"{missing[:3]}"
    )
    bad_uri = [oid for oid in all_oids if not (row_map[oid].storage_uri or "").startswith("mpack://")]
    assert not bad_uri, (
        f"{len(bad_uri)} objects have unexpected storage_uri (expected mpack://...): "
        + str({oid: row_map[oid].storage_uri for oid in bad_uri[:3]})
    )


@pytest.mark.asyncio
async def test_musehub_objects_rows_after_job(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """After mpack.index runs: musehub_objects has one row per object."""
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job
    result = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    raw_objects = mpack.get("blobs") or []
    all_oids = [obj["object_id"] for obj in raw_objects]

    rows = (await db_session.execute(
        select(MusehubObject).where(MusehubObject.object_id.in_(all_oids))
    )).scalars().all()

    assert len(rows) == len(all_oids), (
        f"expected {len(all_oids)} musehub_objects rows, got {len(rows)}"
    )
    # mpack_index_written = number of MusehubMPackIndex rows upserted (one per object).
    assert result["mpack_index_written"] == len(all_oids), result


@pytest.mark.asyncio
async def test_object_refs_after_job(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """After mpack.index runs: musehub_object_refs links every object to this repo."""
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job
    result = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    repo_row = (await db_session.execute(
        select(MusehubRepo).where(MusehubRepo.slug == repo)
    )).scalar_one()

    ref_count = (await db_session.execute(
        select(func.count()).select_from(MusehubObjectRef).where(
            MusehubObjectRef.repo_id == repo_row.repo_id
        )
    )).scalar_one()

    raw_objects = mpack.get("blobs") or []
    assert ref_count == len(raw_objects), (
        f"expected {len(raw_objects)} object_refs rows, got {ref_count}"
    )


@pytest.mark.asyncio
async def test_no_per_object_minio_writes(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """mpack.index must not write per-object MinIO keys.

    sha256(wire_bytes) == mpack_key already authenticated every byte in the
    mpack. Objects are served from the covering mpack via mpack:// URIs;
    individual MinIO keys are never written.
    """
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job
    await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    raw_objects = mpack.get("blobs") or []
    all_oids = [obj["object_id"] for obj in raw_objects]
    rows = (await db_session.execute(
        select(MusehubObject).where(MusehubObject.object_id.in_(all_oids))
    )).scalars().all()

    bad_uri = [r for r in rows if not (r.storage_uri or "").startswith("mpack://")]
    assert not bad_uri, (
        f"{len(bad_uri)} objects have unexpected storage_uri (expected mpack://...): "
        + str({r.object_id: r.storage_uri for r in bad_uri[:3]})
    )


@pytest.mark.asyncio
async def test_job_is_idempotent(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """Running mpack.index twice produces identical DB state to running it once.

    Worker crashes, retries, and duplicate enqueues must all be safe.
    """
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job

    r1 = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    r2 = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    repo_row = (await db_session.execute(
        select(MusehubRepo).where(MusehubRepo.slug == repo)
    )).scalar_one()

    obj_count = (await db_session.execute(
        select(func.count()).select_from(MusehubObjectRef).where(
            MusehubObjectRef.repo_id == repo_row.repo_id
        )
    )).scalar_one()

    raw_objects = mpack.get("blobs") or []
    assert obj_count == len(raw_objects), (
        f"after two runs: expected {len(raw_objects)} object_refs, got {obj_count} "
        "(idempotency failure — rows were doubled)"
    )


@pytest.mark.asyncio
async def test_return_dict_includes_counts_and_timing(
    client: AsyncClient, repo: str, tmp_path: pathlib.Path, db_session: AsyncSession,
) -> None:
    """Return dict contains objects_written, object_refs_written, elapsed_ms."""
    _, head, mpack = _make_repo(tmp_path / "repo")
    job_id = await _push_mpack(repo, mpack, head, db_session)

    from musehub.services.musehub_wire import process_mpack_index_job
    result = await process_mpack_index_job(db_session, job_id)
    await db_session.commit()

    assert "mpack_index_written" in result, result
    assert "commit_graph_written" in result, result
    assert "mpack_size_bytes" in result, result
    assert "elapsed_ms" in result, result
    assert result["mpack_index_written"] >= 0, result
    assert result["mpack_size_bytes"] > 0, result
    assert result["elapsed_ms"] > 0, result